Present in |
Found in the outer layer of the sponge body |
Found in the inner layer of the sponge body |
Cell types |
Flattened epithelial cells (pinacocytes) |
Collar cells or choanocytes |
Function |
Protective layer, involved in maintaining the shape of the sponge |
Choanoderm is involved in water filtration and feeding processes |
Structure |
Single layer of pinacocytes |
Inner layer composed of choanocytes |
Movement of water |
Does not participate in water movement |
Generates water currents through the movement of flagella on choanocytes |
Role in feeding mechanism |
Not involved in feeding processes |
Actively involved in filter-feeding, capturing food particles from water |
Cellular structure |
Cells are flattened and form a protective barrier |
Cells have a collar-like structure with a flagellum, creating water currents |
Function in sponges |
Protective and structural role |
Essential for the sponge’s feeding and nutrient acquisition |